Soon it will be that time when even the last pasture gates close and horses return from the fields back to the stables. The change is enormous for a horse, both physically and mentally. On pasture, summer is often spent enjoying life with friends, moving freely, and eating fresh grass. Moving indoors allows many horses—and owners—to return to routines, train more actively, and experience a certain kind of fresh start. However, when moving to the stable, feeding frequency decreases compared to constant grazing. Horses spend more time indoors and often move less actively in the paddock. These factors are worth taking into account in feeding as well.
From grass to hay
On pasture, the horse eats moist, fresh, and highly digestible grass. Over the summer, the horse’s gut bacteria have become accustomed to fresh forage. On pasture, the horse often moves more than it does when living in a paddock and stable environment. Exercise and the amount of movement also have a significant effect on digestion and gut function. In winter, turnout time is often shorter, and green, moist grass changes into drier, less digestible hay in the stable. Hay is most often available 3–5 times per day. Dry forage slows the moisture content and passage rate of the feed mass moving through the intestines.
Gradual changes reduce the risk of digestive problems
During transition periods, digestive disturbances are common in horses. Gradually implemented feeding changes help the gut microbes adapt to breaking down a different type of diet, and planning an optimal diet supports horses’ health and wellbeing.
The horse’s digestive function is supported by intestinal microbes and bacteria, and these react easily to changes in feeding. If the horse has been on pasture 24/7, it is a good idea a few weeks before moving indoors to bring small amounts of hay to the pasture for the horses to nibble on. This allows the microflora to adapt calmly to the new feed, and it helps avoid many digestive issues—from constipation to diarrhoea or colic. Concentrate amounts are generally recommended to be increased by a maximum of about 200 g per day. The gut micro-organisms react most sensitively to changes in the sugar and protein content of the diet. As the feed changes from moist grass to dry hay, it is also a good idea to check the horse’s drinking amount and ensure adequate salt intake.
However, from the horse’s digestion perspective, moving from pasture to indoors is not as dramatic a change as moving from indoors to pasture. In late summer, pasture grass is usually already higher in fibre, and its energy and protein values are lower than in early summer. The transition can be supported not only by gradual adaptation to feeds, but also by offering stomach-friendly feeds that help the microbiome adapt. Examples include dandelion root, inulin, lactic acid bacteria, or feeds containing beneficial yeasts, such as Tummy Saver, Gastro Control, Gastro Clay B, or Protect That Tummy.
Vitamin needs increase
The indoor feeding season may also mean heavier work for some horses, and therefore energy needs must be adjusted to match the amount and quality of work. If, on the other hand, the horse has gained too much weight over the summer, returning to a normal body condition should be started already in autumn. When moving indoors and switching to dry hay, remember to review the horse’s vitamin and mineral needs as well. In dry hay, the levels of vitamins and other nutrients are lower than in fresh grass.
A horse’s natural feed, fresh grass, contains plenty of precursors of vitamins A, E, and K. When a horse does not eat green grass daily, it needs a vitamin E supplement. A vitamin E supplement is especially important for foals and growing horses, breeding mares, and competition horses in heavy work. Vitamin E is often recommended in small, frequent amounts so that tissue vitamin E levels remain stable. A B-vitamin supplement may be beneficial for all horses during the winter coat growth phase and for the metabolism of normal energy nutrients such as carbohydrates, proteins, and fats. In addition, stressed horses and horses with digestive issues often need a B-vitamin supplement, because in these cases the gut’s own B-vitamin production may be disrupted. Brewer’s yeast contains all the B vitamins a horse needs, and at the same time it also helps balance stomach function. A vitamin D supplement is often needed during winter, especially if the horse spends little time outside or wears a blanket. Vitamin D stores built up during summer cover the horse’s needs for 1–2 months. Vitamin D precursor is found, among other sources, in Iceland moss. Vitamin A is linked especially to immune defence and the wellbeing of skin and mucous membranes. Vitamin A can be obtained, for example, from pasture grass and carrots.
The efficiency with which vitamins obtained directly from feed are converted is linked, among other things, to the horse’s vitamin stores. If the body already has plenty of vitamins, fewer vitamins are converted from precursors for the body’s use. Therefore, high intake from natural feeds is never harmful to the horse. With synthetically produced vitamin supplements, more caution is needed. During forage harvesting, up to 80% of vitamins can be destroyed, after which concentrations decrease during storage by 6–10% per month. During the indoor feeding season, it is therefore important to ensure the horse receives sufficient nutrients and vitamins.
